1. Field of the Invention
The present invention relates to a starting fuel supply control system for internal combustion engines, and more particularly to a starting fuel supply control system which controls the fuel supply to an internal combustion engine equipped with an evaporative emission control system, at the start of the engine.
2. Prior Art
Conventionally, a fuel supply control system for internal combustion engines, is known, e.g. by Provisional Patent Publication (Kokai) No. 57-206738, which operate to determine an amount of fuel supplied to the engine, by correcting a basic fuel amount set depending upon the temperature of the engine, by a correction coefficient set depending upon the rotational speed of the engine.
On the other hand, an evaporative fuel-purging control system for internal combustion engines is widely used, which includes a canister for adsorbing evaporative fuel generated from the fuel tank, a purging passage connecting between the canister and the intake passage for purging a mixture of the evaporative fuel and air therethrough into the intake passage, and a purge control valve arranged across the purging passage for controlling the flow rate of the evaporative fuel supplied to the intake passage.
As is generally known, part of fuel injected into the intake pipe of an internal combustion engine is attached to inner walls of the intake pipe without being gasified or vaporized. The amount of fuel attached to the inner walls is large particularly at the start of the engine and before completion of warming-up of the engine. To compensate for the attached fuel amount, the above-mentioned conventional fuel supply control system is designed to inject a larger amount of fuel than the amount actually required by the engine.
However, the injection of such an excessive amount of fuel causes emission of an unburnt component (HC) in large quantities, resulting in degraded exhaust emission characteristics, as well as in increased fuel consumption.